In this surgery, there are two procedures that occur. First, the surgeon will create a small pouch out of the top of the stomach, about 1 ounce (30 milliliters) in volume, separating it from the rest of the stomach. Then, the small intestine gets divided into two segments as well. The small pouch created out of stomach is connected to the bottom portion of the small intestine, hence bypassing the top portion of the small intestine. The procedure is completed by attaching the top portion of the small intestine to the bottom portion of the small intestine, further down, so that stomach acids and digestive enzymes will eventually mix with the food ingested.